Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Asymmetric Synthesis of ?-Lactones through Koga Amine-Controlled Addition of Enediolates to ?,?-Unsaturated Sulfoxonium Salts.

ABSTRACT: A chiral Koga amine-controlled asymmetric synthesis of cis-?-lactones through a formal [3 + 2] cycloaddition of enediolates with ?,?-unsaturated sulfoxonium salts is described. The desired structural motif was formed in moderate to good yields (50-71% for 13 examples), with good to very good diastereoselectivity (dr 5:1 to 10:1 for 20 examples), favoring the cis-isomer, and good to excellent enantioselectivity (70-91% ee for 13 examples).

SUBMITTER: Peraino NJ

PROVIDER: S-EPMC5591458 | biostudies-literature | 2017 Jan

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Asymmetric Synthesis of γ-Lactones through Koga Amine-Controlled Addition of Enediolates to α,β-Unsaturated Sulfoxonium Salts.

Peraino Nicholas J NJ Kaster Sven H SH Wheeler Kraig A KA Kerrigan Nessan J NJ

The Journal of organic chemistry 20161209 1

A chiral Koga amine-controlled asymmetric synthesis of cis-γ-lactones through a formal [3 + 2] cycloaddition of enediolates with α,β-unsaturated sulfoxonium salts is described. The desired structural motif was formed in moderate to good yields (50-71% for 13 examples), with good to very good diastereoselectivity (dr 5:1 to 10:1 for 20 examples), favoring the cis-isomer, and good to excellent enantioselectivity (70-91% ee for 13 examples). ...[more]

PMID: 27933807

Similar Datasets

Organocatalytic asymmetric synthesis of α-amino esters from sulfoxonium ylides.

Project description:Described here is the first organocatalytic asymmetric N-H insertion reaction of α-carbonyl sulfoxonium ylides. Without a metal catalyst, this reaction represents an attractive complement to the well-established carbene insertion reactions. As a stable surrogate of diazocarbonyl compounds, sulfoxonium ylides reacted with a range of aryl amines to provide efficient access to α-aryl glycines with excellent enantiocontrol in the presence of a suitable chiral phosphoric acid catalyst. The high stability and weak basicity of sulfoxonium ylides not only enable this protocol to be user-friendly and practically useful, but also preclude catalyst decomposition, which is crucial to the excellent amenability to electron-poor amine nucleophiles. Detailed mechanistic studies indicated that the initial protonation is reversible and the C-N bond formation is rate-determining.

| S-EPMC8386753 | biostudies-literature

Organocatalytic asymmetric addition of malonates to unsaturated 1,4-diketones.

Project description:The organocatalytic Michael addition of malonates to symmetric unsaturated 1,4-diketones catalyzed by thiourea and squaramide derivatives with Cinchona alkaloids afforded the formation of a new C-C bond in high yields (up to 98%) and enantiomeric purities (up to 93%). The absolute configuration of the product was suggested from comparison of the experimental and calculated VCD spectra of the reaction product 3a.

| S-EPMC3458770 | biostudies-literature

Lactones 41. Synthesis and microbial hydroxylation of unsaturated terpenoid lactones with p-menthane ring systems.

Project description:Racemic [(±)-4-isopropyl-1-methyl-7-oxa-cis-bicyclo[4.3.0]non-4-en-8-one] and optically active δ,ε-unsaturated lactones [(-)-(1R,6R)-4-isopropyl-1-methyl-7-oxabicyclo[4.3.0]non-4-en-8-one and (+)-(1S,6S)-4-isopropyl-1-methyl-7-oxabicyclo[4.3.0] non-4-en-8-one)] with the p-menthane system were obtained and their odoriferous properties were evaluated. Biotransformations of the racemic lactone with three fungal strains: Absidia cylindrospora AM336, Absidia glauca AM177 and Syncephalastrum racemosum AM105, were carried out. Microbial transformations afforded hydroxylactones with the hydroxy group in the allylic position.

| S-EPMC6269982 | biostudies-literature

Asymmetric synthesis of ?-alkenyl homoallylic primary amines via 1,2-addition of Grignard reagent to ?,?-unsaturated phosphonyl imines.

Project description:A series of chiral N-phosphonyl protected ?-alkenyl homoallylic primary amines were synthesized by asymmetric addition of allylmagnesium bromide Grignard reagent towards chiral ?,?-unsaturated imines. Only 1,2-adduct was obtained for all the imines with good yields and excellent diastereoselectivities. The chiral auxiliary could be easily removed under simple conditions, giving free multiple functionalized primary amines.

| S-EPMC3804338 | biostudies-literature

Catalytic asymmetric addition of diphenylzinc to cyclic alpha,beta-unsaturated ketones.

Project description:We have examined the use of our bis(sulfonamide) diol ligand (1) in the asymmetric addition of phenyl groups to cyclic alpha,beta-unsaturated ketones. Good to excellent enantioselectivities have been obtained with cyclic enones bearing alkyl substituents in the 2 position (71-97% enantiomeric excess). Furthermore, excellent enantioselectivities have been observed in the asymmetric phenylation of cyclic enones with 2-iodo and 2-bromo substituents. The results of this study broaden the scope of the asymmetric additions to ketones promoted by the titanium catalyst derived from ligand 1.

| S-EPMC397398 | biostudies-literature

Synthesis of Enantioenriched 2-Alkyl Piperidine Derivatives through Asymmetric Reduction of Pyridinium Salts.

Project description:An Ir-catalyzed enantioselective hydrogenation of 2-alkyl-pyridines has been developed using ligand MeO-BoQPhos. High levels of enantioselectivities up to 93:7 er were obtained. The resulting enantioenriched piperidines can be readily converted into biologically interesting molecules such as the fused tricyclic structures 5, 6, and 7 in 99:1 er, providing a novel, concise synthetic route to this family of chiral piperidine-containing compounds.

| S-EPMC10405300 | biostudies-literature

Catalytic Asymmetric Synthesis of Ketene Heterodimer ?-Lactones: Scope and Limitations.

Project description:In this article we describe extensive studies of the catalytic asymmetric heterodimerization of ketenes to give ketene heterodimer ?-lactones. The optimal catalytic system was determined to be a cinchona alkaloid derivative (TMS-quinine or Me-quinidine). The desired ketene heterodimer ?-lactones were obtained in good to excellent yields (up to 90%), with excellent levels of enantioselectivity (?90% ee for 33 Z and E isomer examples), good to excellent (Z)-olefin isomer selectivity (?90:10 for 20 examples), and excellent regioselectivity (only one regioisomer formed). Full details of catalyst development studies, catalyst loading investigations, substrate scope exploration, protocol innovations (including double in situ ketene generation for 7 examples), and an application to a cinnabaramide A intermediate are described. The addition of lithium perchlorate (1-2 equiv) as an additive to the alkaloid catalyst system was found to favor formation of the E isomer of the ketene heterodimer. Ten examples were formed with moderate to excellent (E)-olefin isomer selectivity (74:25 to 97:3) and with excellent enantioselectivity (84-98% ee).

| S-EPMC5012991 | biostudies-literature

Asymmetric vinylogous aldol addition of alkylidene oxindoles on trifluoromethyl-α,β-unsaturated ketones.

Project description:A novel vinylogous aldol addition of alkylidene oxindole with 1-trifluoromethyl-3-alkylidene-propan-2-ones is presented. The reaction, catalyzed by a bifunctional tertiary amine, provides an efficient application of the vinylogous reactivity of oxindoles for the preparation of enantioenriched trifluoromethylated allylic alcohols.

| S-EPMC9086480 | biostudies-literature

Substrate encapsulation: an efficient strategy for the RCM synthesis of unsaturated epsilon-lactones.

Project description:A facile substrate-encapsulated RCM-based synthesis of 7-membered lactones is reported. Coordination of the alpha,omega-dienyl ester precursor to the bulky Lewis acid (LA) aluminum tris(2,6-diphenylphenoxide) (ATPH) provides a protective extended steric pocket to the olefin moieties, thereby favoring intramolecular RCM over intermolecular ADMET oligomerization. The LA-encapsulated esters undergo ring-closure in the presence of Ru-based olefin metathesis catalysts to give previously difficult-to-access 7-membered beta,gamma- and gamma,delta-unsaturated lactones in good yields.

| S-EPMC3083066 | biostudies-literature

Synthesis and Biotransformation of Bicyclic Unsaturated Lactones with Three or Four Methyl Groups.

Project description:The aim of this study was to obtain new unsaturated lactones by chemical synthesis and their microbial transformations using fungal strains. Some of these strains were able to transform unsaturated lactones into different hydroxy or epoxy derivatives. Strains of Syncephalastrum racemosum and Absidia cylindrospora gave products with a hydroxy group introduced into a tertiary carbon, while the Penicillium vermiculatum strain hydroxylated primary carbons. The Syncephalastrum racemosum strain hydroxylated both substrates in an allylic position. Using the Absidia cylindrospora and Penicillium vermiculatum strains led to the obtained epoxylactones. The structures of all lactones were established on the basis of spectroscopic data.

| S-EPMC6155629 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data